/*
 * Aspire Hearthstone
 * Copyright (C) 2008 - 2009 AspireDev <http://www.aspiredev.org/>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "BigNumber.h"
#include <openssl/bn.h>
#include <algorithm>

BigNumber::BigNumber()
{
	_bn = BN_new();
	_array = NULL;
}

BigNumber::BigNumber(const BigNumber &bn)
{
	_bn = BN_dup(bn._bn);
	_array = NULL;
}

BigNumber::BigNumber(uint32 val)
{
	_bn = BN_new();
	BN_set_word(_bn, val);
	_array = NULL;
}

BigNumber::~BigNumber()
{
	BN_free(_bn);
	delete[] _array;
}

void BigNumber::SetDword(uint32 val)
{
	BN_set_word(_bn, val);
}

void BigNumber::SetQword(uint64 val)
{
	BN_add_word(_bn, (uint32)(val >> 32));
	BN_lshift(_bn, _bn, 32);
	BN_add_word(_bn, (uint32)(val & 0xFFFFFFFF));
}

void BigNumber::SetBinary(const uint8 *bytes, int len)
{
	uint8 t[1000];
	for (int i = 0; i < len; i++) t[i] = bytes[len - 1 - i];
	BN_bin2bn(t, len, _bn);
}

void BigNumber::SetHexStr(const char *str)
{
	BN_hex2bn(&_bn, str);
}

void BigNumber::SetRand(int numbits)
{
	BN_rand(_bn, numbits, 0, 1);
}


BigNumber BigNumber::operator=(const BigNumber &bn)
{
	BN_copy(_bn, bn._bn);
	return *this;
}

BigNumber BigNumber::operator+=(const BigNumber &bn)
{
	BN_add(_bn, _bn, bn._bn);
	return *this;
}

BigNumber BigNumber::operator-=(const BigNumber &bn)
{
	BN_sub(_bn, _bn, bn._bn);
	return *this;
}

BigNumber BigNumber::operator*=(const BigNumber &bn)
{
	BN_CTX *bnctx;

	bnctx = BN_CTX_new();
	BN_mul(_bn, _bn, bn._bn, bnctx);
	BN_CTX_free(bnctx);

	return *this;
}

BigNumber BigNumber::operator/=(const BigNumber &bn)
{
	BN_CTX *bnctx;

	bnctx = BN_CTX_new();
	BN_div(_bn, NULL, _bn, bn._bn, bnctx);
	BN_CTX_free(bnctx);

	return *this;
}

BigNumber BigNumber::operator%=(const BigNumber &bn)
{
	BN_CTX *bnctx;

	bnctx = BN_CTX_new();
	BN_mod(_bn, _bn, bn._bn, bnctx);
	BN_CTX_free(bnctx);

	return *this;
}

BigNumber BigNumber::Exp(const BigNumber &bn)
{
	BigNumber ret;
	BN_CTX *bnctx;

	bnctx = BN_CTX_new();
	BN_exp(ret._bn, _bn, bn._bn, bnctx);
	BN_CTX_free(bnctx);

	return ret;
}

BigNumber BigNumber::ModExp(const BigNumber &bn1, const BigNumber &bn2)
{
	BigNumber ret;
	BN_CTX *bnctx;

	bnctx = BN_CTX_new();
	BN_mod_exp(ret._bn, _bn, bn1._bn, bn2._bn, bnctx);
	BN_CTX_free(bnctx);

	return ret;
}

int BigNumber::GetNumBytes(void)
{
	return BN_num_bytes(_bn);
}

uint32 BigNumber::AsDword()
{
	return (uint32)BN_get_word(_bn);
}

uint8 *BigNumber::AsByteArray()
{
	if (_array) {
		delete[] _array;
		_array = NULL;
	}
	_array = new uint8[GetNumBytes()];
	BN_bn2bin(_bn, (unsigned char *)_array);

	std::reverse(_array, _array + GetNumBytes());

	return _array;
}

ByteBuffer BigNumber::AsByteBuffer()
{
	ByteBuffer ret(GetNumBytes());
	ret.append(AsByteArray(), GetNumBytes());
	return ret;
}

std::vector<uint8> BigNumber::AsByteVector()
{
	std::vector<uint8> ret;
	ret.resize(GetNumBytes());
	memcpy(&ret[0], AsByteArray(), GetNumBytes());
	return ret;
}

const char *BigNumber::AsHexStr()
{
	return BN_bn2hex(_bn);
}

const char *BigNumber::AsDecStr()
{
	return BN_bn2dec(_bn);
}
